Question: In language class, the girl to boy ratio is $9$ to $10$. If there are a total of $76$ students, how many boys are there?
A ratio of $9$ girls to $10$ boys means that a set of $19$ students will have $9$ girls and $10$ boys. A class of $76$ students has $4$ sets of $19$ students. Because we know that there are $10$ boys in each set of $19$ students, the class must have $4$ groups of $10$ boys each. There is a total of $40$ boys in language class.